If two lines are perpendicular, then the product of their slope is _____.
0
1
-1
infinite
Two non-vertical lines are perpendicular if and only if the product of their slopes is -1
Two non-vertical lines are perpendicular if and only if the product of their slopes is 1.
When two lines of slopes m1 & m2 are perpendicular to each other. Product of their slopes is 1